As a result of a court challenge
to the 1997 ozone and PM2.5 standards, on March 26, 2002, the
U.S. Court of Appeals for the District of Columbia decided on
the Petitioners' specific challenges to the air quality standards
that remained unresolved. The Court rejected the argument that
the language and reasoning of their earlier decision determined
the outcome of these remaining claims. Finding the challenged
air quality standards neither arbitrary nor capricious, the Court
of Appeals denied the petitions for review except to the extent
the Supreme Court's and their earlier decisions require further
action by EPA.

Earlier, on May 14, 1999,
the U.S. Court of Appeals for the D.C. Circuit set aside the
new air quality standards issued by the Environmental Protection
Agency in July 1997. The court remanded the ozone and fine particulate
matter (PM2.5) standards to the EPA for redrafting and ordered
the agency to explain why its rule-making process was justified
under the Constitution. The PM10 standard was revoked.

By a 2 to 1 vote, the court
concluded the EPA set the new pollution levels arbitrarily without
clear "principles" to support them. The nondelegation
doctrine requires such a principle. In their decision, the judges
wrote, in adopting the guidelines two years ago, the Environmental
Protection Agency had failed to show that additional health protections
were justified, ruling that the agency had acted on legal assumptions
that amounted to "unconstitutional delegations of legislative
power." Judge Tatel dissented from this portion of the opinion,
but concurred in the remainder of the decisions.

Some background on the "unconstitutional
delegations of legislative power" decision would be helpful
here. The decision points out a growing contradiction in air
pollution policy. Congress told the EPA to set standards that
protect the public's health with "an adequate margin of
safety," on the theory that there is a threshold below which
any pollutant is safe. But some scientists argue that for contaminants,
such as ozone, any exposure level may be harmful.

EPA regards ozone definitely,
and particulate matter likely, as non-threshold pollutants (i.e.,
ones that have some possibility of some adverse health impact,
however slight, at any exposure level above zero). Thus the only
concentration for ozone and particulate matter that is utterly
risk-free, in the sense of direct health impacts, is zero. In
its ruling, the court stated

Section 109(b)(1) says that
EPA must set each standard at the level "requisite to protect
the public health" with an "adequate margin of safety."
42 U.S.C. s 7409(b)(1). These are also the criteria by which
EPA must determine whether a revision to existing NAAQS is appropriate.
See 42 U.S.C. s 7409(d)(1) (EPA shall "promulgate such new
standards as may be appropriate in accordance with ... [s 7409(b)]");
see also infra Part II.A. For EPA to pick any non-zero level
it must explain the degree of imperfection permitted. The factors
that EPA has elected to examine for this purpose in themselves
pose no inherent nondelegation problem. But what EPA lacks is
any determinate criterion for drawing lines. It has failed to
state intelligibly how much is too much.

As an example of not explicitly
determining criteria for basing its decisions, the court provided
an example. The judges noted

...that EPA argued that a
0.07 standard would be "closer to peak background levels
that infrequently occur in some areas due to nonanthropogenic
sources of O3 precursors, and thus more likely to be inappropriately
targeted in some areas on such sources." But a 0.08 level,
of course, is also closer to these peak levels than 0.09. The
dissent notes that a single background observation fell between
0.07 and 0.08, and says that EPA's decision" ensured that
if a region surpasses the ozone standard, it will do so because
of controllable human activity, not uncontrollable natural levels
of ozone." EPA's language, coupled with the data on background
ozone levels, may add up to a backhanded way of saying that,
given the national character of the NAAQS, it is inappropriate
to set a standard below a level that can be achieved throughout
the country without action affirmatively extracting chemicals
from nature. That may well be a sound reading of the statute,
but EPA has not explicitly adopted it.

The court found that EPA is
precluded from enforcing a revised primary ozone NAAQS other
than in accordance with the classifications, attainment dates,
and control measures set out in Subpart 2 of the Clean Air Act.
The Court agreed that "because the 1990 amendments extended
the time for nonattainment areas to comply with the 0.12 ppm
ozone NAAQS, they must preclude the EPA from requiring areas
to comply either more quickly or with a more stringent ozone
NAAQS."

The appeals court rejected
claims by the industry groups that the regulations were based
on incomplete and poor science, or that the EPA should have taken
costs into account.

In an interesting decision,
the court found that EPA must consider health disbenefits of
proposed standards as well as benefits. The court concluded that
EPA must consider the increased risk of skin cancers that could
result from the new ozone standard. The court remanded to EPA
"to formulate adequate decision criteria" for analysis
of both health benefits and risks presented by the standard,
and to use those decision criteria to determine whether tropospheric
ozone has a beneficial effect on health, and if so, "assess
ozone's net adverse health effect by whatever criteria it adopts."

The court found that PM10
was not an appropriate indicator for coarse particles because
it includes fine particles in its measurement. In the court's
view, this amounts to double regulation of PM2.5 and underregulation
of coarse particles (i.e., particles between 2.5 and 10 micrometers
in size). Accordingly, the PM10 standard was vacated and the
judges directed the EPA to develop a new one.

The court did not vacate the
EPA's ozone rule altogether, but said the standard "cannot
be enforced." The court believes that the ozone standard
is unlikely to engender costly compliance activities in light
of the determination that it cannot be enforced by virtue of
the Clean Air Act.

While the court process was
playing out, EPA had indicated that the Agency was going to

proceed with its proposal
for cleaner vehicles and cleaner gasoline;

ensure the air quality
monitoring program continues and the PM 2.5 monitors are put
in place;

continue support for voluntary
"right-to-know" programs managed by states and coordinated
through EPA, such as the Ozone Action Days and the air quality
data submitted to EPA's Internet Ozone Mapping Site; and

designate areas as attainment
or nonattainment for the 8-hour ozone standard.

On October 29, 1999, the U.S.
Court of Appeals for the D.C. Circuit rejected a request by the
Environmental Protection Agency to reconsider a ruling that struck
down the agency's new 8-hour and PM national air pollution standards.
The court denied the EPA's appeal for a rehearing by all 11 judges
of a ruling in May that the EPA had overstepped its constitutional
authority in adopting the standards two years ago. Of the 11
judges on the appeals court, two did not participate and five
voted to rehear the case. The appeals court requires six votes
to review a case.

On January 28, 2000, the Justice
Department, on behalf of the EPA, filed a petition for certiorari
with the U.S. Supreme Court The EPA appealed the following three
issues:

Whether Section 109 of
the Clean Air Act, 42 U.S.C. 7409, as interpreted by the Environmental
Protection Agency (EPA) in setting revised National Ambient Air
Quality Standards (NAAQS) for ozone and particulate matter, effects
an unconstitutional delegation of legislative power;

Whether the court of appeals
exceeded its jurisdiction by reviewing, as a final agency action
that is ripe for review, EPA's preliminary preamble statements
on the scope of the agency's authority to implement the revised
"eight-hour" ozone NAAQS; and

Whether provisions of
the Clean Air Act Amendments of 1990 specifically aimed at achieving
the long-delayed attainment of the then-existing ozone NAAQS
restrict EPA's general authority under other provisions of the
CAA to implement a new and more protective ozone NAAQS until
the prior standard is attained.

EPA did not appeal the D.C.
Circuit's finding that the Agency must consider all health effects,
both negative and positive, in setting a standard.

On November 7, 2000, the Supreme
Court heard the case about the D.C. Circuit's decision remanding
the ozone and particulate matter national ambient air quality
standards to the EPA. In addition, the Court also heard the cross-appeal
by the U.S. Chamber of Commerce, the American Trucking Associations,
and others. The challengers asked the justices to review those
portions of the appeals court ruling that freed the EPA from
taking costs into account and rejected the groups' contention
that the air-quality standards were based on incomplete and poor
science.

On February 27, 2001, the
Supreme Court upheld the way the federal government sets clean-air
standards, rejecting industry arguments that officials must balance
compliance costs against the health benefits of cleaner air.
The justices also ruled against industry arguments that the Environmental
Protection Agency took too much lawmaking power from Congress
when it set tougher standards for ozone and soot in 1997. However,
the court ordered the EPA to reconsider the standards it set
for ozone, saying the agency's interpretation of a section of
the Clean Air Act was unreasonable. The justices ruled against
the EPA's implementation of revised ozone standards in areas
whose ozone levels exceed the maximum allowable amount. The justices
held that the EPA had ignored the law, which in 1990, allowed
many regions extra time to meet the air quality standards. The
Court wrote that Congress would hardly have intended for the
EPA to adopt the tougher 1997 rules and enforce them immediately.

The U. S. Supreme Court summarized
the holdings of the complex cases of Whitman, Administrator of
the U.S. EPA et al. versus American Trucking Associations, Inc.
et al. that was argued on November 7, 2000.

(1) The EPA may not consider
implementation costs in setting primary and secondary NAAQS under
Section 109(b) of the Clean Air Act (CAA).

(2) Section 109(b)(1) of the
CAA does not delegate legislative power to the EPA in contravention
of Art. I, Sect. 1, of the Constitution.

(3) The Court of Appeals had
jurisdiction to review the EPA's
interpretation of Part D of Title I of the CAA, relating to the
implementation of the revised ozone NAAQS.

(4) The EPA's interpretation
of that Part is unreasonable.

In regard to (4) above, the
Supreme Court found "the EPA's implementation policy to
be unlawful, though not in the precise respect determined by
the Court of Appeals. After remand, and the Court of Appeals
final disposition of this case, it left to the EPA to develop
a reasonable interpretation of the nonattainment implementation
provisions insofar as they apply to revised ozone NAAQS.

The judgment of the Court
of Appeals, therefore, is affirmed in part and reversed in part,
and the cases are remanded for proceedings consistent with the
opinion.

On December 22, 2006, the DC Circuit Court
of Appeals announced its ruling on EPAs April 2004 Phase
1 Rule to implement the 8-hour ozone National Ambient Air Quality
Standard. The unanimous ruling vacated the rule. In EPAs
2004 rule, 8-hour ozone nonattainment areas were classified into
Subpart 1 or Subpart 2, EPA distinguished between the two classifications
based on the areas 1-hour ozone design value at the time
of designation. If an areas 1-hour ozone design value exceeded
0.121 ppm, the area was classified as Subpart 2. If an area only
exceeded the 8-hour ozone design value of 0.085 ppm, but not
the 0.121 ppm 1-hour design value, the area was designated as
Subpart 1.

The court ruled that the Clean Air Act mandated
that EPA should have applied the 8-hour design value equivalent
in stringency to the old 1-hour standard, which EPA had calculated
to be an 8-hour level of 0.09 ppm. The court ruled that for areas
with 8-hour ozone design values between 0.08 and 0.09 ppm, where
the Clean Air Act did not mandate a certain procedure, EPA did
not adequately support classifying these areas under Subpart
1. If you care to read the DC Circuit Court of Appeals' decision,
please click
here.

On September 21, 2006, EPA
announced with regard to primary standards for fine particles
(generally referring to particles less than or equal to 2.5 micrometers
(µm) in diameter, PM2.5) that it was revising the level
of the 24-hour PM2.5 standard to 35 micrograms per cubic meter
(µg/m3) and retaining the level of the annual PM2.5 standard
at 15 µg/m3. With regard to primary standards for particles
generally less than or equal to 10 µm in diameter (PM10),
EPA is retaining the 24-hour PM10 and revoking the annual PM10
standard. With regard to secondary PM standards, EPA is making
them identical in all respects to the primary PM standards, as
revised. The issue of reliability of the epidemiological time-series
methodologies continues to be of concern to the Administrator.
The Administrator noted in his decision that there were many
sources of uncertainty and variability inherent in the inputs
to the assessment and that there was a high degree of uncertainty
in the resulting PM2.5 risk estimates. Such uncertainties generally
related to a lack of clear understanding of a number of important
factors, including, for example, the shape of concentration-response
functions, particularly when, as here, effect thresholds can
neither be discerned nor determined not to exist; issues related
to selection of appropriate statistical models for the analysis
of the epidemiologic data; and the role of potentially confounding
and modifying factors in the concentration-response relationships.
For those interested in the possible violation areas for the
revised 24-hour PM-2.5 standard based on 2004-2005 data, please
click here.

On December 15, 2006, public health and environmental
groups filed suit against the U.S. EPA for refusing to strengthen
the PM-2.5 annual standard.On February 24, 2009, as a result of
the suit filed against the U.S. EPA by
public health and environmental groups, the U.S. Court of Appeals
for the D.C. Circuit remanded the National Ambient Air Quality
Standards (NAAQS) for fine particulate matter (PM2.5) to EPA
for reconsideration of the annual level of the standard (which
EPA left at 15 micrograms per cubic meter (µg/m3)) and
reconsideration of the secondary PM2.5 NAAQS. With respect to
the annual PM2.5 NAAQS, the court held that the agency failed
to explain adequately why an annual level of 15 µg/m3 is
requisite to protect the public health, including
the health of vulnerable subpopulations, while providing an
adequate margin of safety. 42 U.S.C.§ 7409(b)(1).
For the secondary standards, the court held that EPA unreasonably
concluded that the NAAQS are adequate to protect the public welfare
from adverse effects on visibility. The court denied petitions
for review of the primary daily standard for coarse PM and the
petition for review of EPAs revocation of the primary annual
standard for coarse PM. The Court opinion can be read by clicking
here.

In May 27, 2008, health and
environmental organizations filed a lawsuit arguing that the
EPA failed to protect public health and the environment when
it issued in March 2008 new ozone standards. On March 10, 2009,
the US EPA requested that the Court vacate the existing briefing
schedule and hold the consolidated cases in abeyance. EPA requested
the extension to allow time for appropriate EPA officials that
are appointed by the new Administration to review the Ozone NAAQS
Rule to determine whether the standards established in the Ozone
NAAQS Rule should be maintained, modified, or otherwise reconsidered.
EPA further requested that it be directed to notify the Court
and the Parties within 180 days of the Court's order vacating
the briefing schedule of the actions the Agency has taken or
intends to take, if any, with regard to the Ozone NAAQS Rule,
and the anticipated time frame for any such actions.

On September 16, 2009, the
EPA announced it would reconsider the 2008 national ambient air
quality standards (NAAQS) for ground-level ozone for both human
health and environmental effects. The Agency planned to propose
any needed revisions to the ozone standards by December 2009
and issue a final decision by August 2010. On January 7, 2010,
the EPA announced on its web site its proposal to strengthen
the national ambient air quality standards for ground-level ozone.
The EPA's proposal decreased the 8-hour primary ozone
standard level, designed to protect public health, to a level
within the range of 0.060-0.070 parts per million (ppm). EPA
also proposed to establish a distinct cumulative, seasonal secondary
standard, referred to as the W126 index, which was designed to protect
sensitive vegetation and ecosystems, including forests, parks,
wildlife refuges, and wilderness areas. EPA proposed to set the
level of the W126 secondary standard within the range
of 7-15 ppm-hours. On August 20, the Agency announced that it
would delay its final announcement to on or around the end of
October. In early November, the EPA announced that it would reach
a final decision on the ozone standards by December 31, 2010.
On December 8, the EPA announced that it would delay its final
decision on the ozone standards until July 2011. EPA announced
on July 26 that it would not make a decision on the ozone standards
by its previously announced deadline of July 29. On September
2, 2011, President Obama requested that the EPA withdraw its
proposed revisions to the ozone standards. The proposed revisions
result from a reconsideration of the identical primary and secondary
ozone standards set at 0.075 ppm in March 2008.

In response to a series of
lawsuits, on July 23, 2013, the D.C. Circuit issued its opinion
in the 2008 ozone NAAQS litigation. The court denied the petitions
for review of both industry and the states/environmental groups
challenging the primary ozone NAAQS. In other words, the court
upheld the 0.075 ppm primary standard and is not requiring EPA
to lower the NAAQS further. The court remanded the secondary
ozone NAAQS to EPA because it found that EPA had failed to justify
setting the secondary standard at the same level as the primary.
The decision makes interesting reading and is available by clicking
here.